Garver-led pilot testing program aids long-time client

When one of the largest secondary treatment facilities in Little Rock, Arkansas was experienced decreased ultraviolet transmittance following increased flow rates, Garver’s expert Water Team developed a pilot testing program to research an alternative to reach adequate disinfection levels through supplemental peracetic acid (PAA) before the ultraviolet (UV) system.

Garver assisted the Little Rock Water Reclamation Authority (LRWRA), which operates the Adams Field Water Reclamation Facility (WRF), in the development of a five-week pilot testing program, followed by a full-scale trial, both of which assessed the benefits of sequential disinfection with PAA followed by UV. Garver provided design and planning for PAA storage, and all essential equipment for on-site disinfectant testing and data analyses, which was used to successfully implement full-scale testing of supplemental disinfection with PAA at the reclamation facility.

For its work on the project, Garver was awarded an Engineering Excellence Award in the water and wastewater category from the American Council of Engineering Companies of Arkansas.

“The data collected highlights the critical role that PAA can play in meeting effluent limits when effluent ultraviolet transmittance is impaired,” said Senior Project Manager Paul Strickland. “This program highlights the Little Rock Water Reclamation Authority’s willingness to find creative and effective ways of improving the performance of its disinfection facility.”

PAA represents a potential new trend for wastewater disinfection, as in many applications, it will not require residual disinfectant quenching before discharge to the receiving body of water.

Because no current regulations govern the construction and operation of PAA disinfection facilities in Arkansas, Garver and LRWRA worked closely with the Arkansas Department of Environmental Quality to develop the pilot test for on-site disinfection. The full-scale test proved effective for managing effluent at elevated facility flows, reduced effluent UVT, and has helped determine the true cost of operations for PAA and UV for sequential disinfection.